تنوع ژنوتیپ‌های تیپ آمیزشی، گروه‌های سازگار میسلیومی و توان تهاجم جدایه‌های sclerotinia sclerotiorum به‌دست آمده از مزارع آفتابگردان و کلم استان آذربایجان غربی

قارچ sclerotinia sclerotiorum (lib.) de bary یک بیمارگر مهم با پراکنش جهانی است که طیف وسیعی از گیاهان را مورد حمله قرار می‌دهد. در این مطالعه، تنوع ژنوتیپ‌های تیپ‌های آمیزشی، گروه‌های سازگار میسلیومی و توان تهاجم 136 جدایه به‌دست آمده از مزارع آفتابگردان و کلم واقع در مناطق مختلف استان آذربایجان غربی مورد بررسی قرار گرفت. بررسی تیپ‌های آمیزشی جدایه‌ها وجود هر سه ژنوتیپ را در جمعیت‌ها نشان داد و 54 درصد از جدایه‌ها به عنوان ژنوتیپ inv– mat شناسایی شدند. جدایه‌های مورد بررسی در 17 گروه سازگار میسلیومی (mcg1 تا mcg17) قرار گرفتند که اعضای برخی از آنها در بیش از یک منطقه و روی هر دو میزبان دیده شدند. با این‌که جدایه‌ها از لحاظ توان تهاجم روی برگ‌های بریده آفتابگردان و کلم متنوع بودند، اما فقط چند جدایه با بیشترین توان تهاجم، اختلاف معنی‌داری با سایر جدایه-ها داشتند. میانگین توان تهاجم جدایه‌های متعلق به مناطق، میزبان‌ها، گروه‌های سازگار میسلیومی و ژنوتیپ‌های تیپ‌های آمیزشی اختلاف معنی‌داری با همدیگر در سطح احتمال یک درصد داشتند. در مجموع، به دلیل تنوع توان تهاجم جدایه‌ها و وجود ژنوتیپ هتروکاریون و نیز وارونگی در مکان ژنی تیپ آمیزشی که بیانگر وقوع تولیدمثل جنسی در قارچ است، به نظر می‌رسد که جمعیت‌های قارچ در استان پتانسیل فرگشتی و توان سازگاری بالایی دارند که می‌توانند کارآیی روش‌های کنترل این بیمارگر را تحت تاثیر قرار دهد. برای افزایش کارآیی و پایداری مقاومت ارقام، غربالگری ارقام باید با استفاده از جدایه‌های متعدد از گروه‌های سازگار میسلیومی، مناطق و میزبان‌های مختلف انجام گیرد.

variation in mating type genotypes, mycelial compatibility groups, and aggressiveness of sclerotinia sclerotiorum isolates from sunflower and cabbage fields of west azarbaijan province

background and objectivessclerotinia sclerotiorum (lib.) de bary is a globally distributed necrotrophic fungus that infects a wide range of plants. the management of this pathogen in crops typically requires a combination of methods, with resistant cultivars and fungicide applications being the most commonly used strategies. it is essential to comprehend the evolutionary potential of s. sclerotiorum in a specific region in order to effectively control this pathogen, conduct germplasm evaluations, and develop resistant cultivars. an in-depth analysis of aggressiveness variation, diversity and distribution of mycelial compatibility groups (mcgs), and the occurrence of sexual reproduction via the methods, such as mating type genotype determination can provide valuable insights into the genetic diversity, and evolutionary potential of this fungus. in west azarbaijan province, s. sclerotiorum poses a significant threat to sunflower and cabbage crops, causing considerable losses. nevertheless, there is a dearth of research that compares the aggressiveness diversities and mcg of fungal isolates from these two hosts. additionally, there is presently no information available regarding the mating type genotypes of the pathogen populations in the province and other regions of the country. this study was conducted to investigate, and compare mcgs and aggressiveness diversity in s. sclerotiorum populations from sunflower, and cabbage fields in west azarbaijan province. the research also aimed to identify mating type genotypes, and compare their aggressiveness diversity.materials and methodsthis study examined 136 s. sclerotiorum isolates collected from sunflower, and cabbage fields in urmia, salmas, and khoy in west azarbaijan province, iran. the mating type alleles of the isolates were determined using specific primers. isolates in which either inv+ mat (inversion positive) or inv– mat allele was detected were classified as inv+ mat or inv– mat genotype, respectively. isolates showing amplification of both alleles were categorized as heterokaryon genotypes. the mcgs of isolates were determined by pairing them in all possible combinations on potato dextrose agar supplemented with mccormick food color. the number of mcgs was determined both for total isolates and for each of the populations. to evaluate mcg diversity, mcg richness (ratio of different mcgs) was calculated for the populations. the level of aggressiveness of 80 specific isolates was evaluated by inoculating them on detached leaves of sunflower and cabbage, and then measuring the diameters of the resulting lesions five days after the inoculation. lesion diameter data were normalized via logarithmic transformation, and analyzed using a general linear model in minitab 17 software. means were compared using tukey–kramer honestly significant difference (hsd) test at a significance level of p < 0.05.resultsthe specific primers successfully amplified mat alleles in the studied isolates, leading to the identification of three genotypes, inv– mat, inv+ mat, and heterokaryon, within 136 s. sclerotiorum isolates. these genotypes were distributed as follows: 74 isolates (54.41%) were inv– mat, 22 isolates (16.18%) were inv+ mat, and 40 isolates (29.41%) were heterokaryon. while all three mat genotypes were present across all geographical regions, and on both host plants, the inv– mat genotype was the most frequent genotype in all regions and on sunflower, while heterokaryon genotype was more common among cabbage isolates. a total of 17 mcgs, designated mcg1 to mcg17, were identified in the 136 isolates. eleven of these mcgs had multiple isolates, with mcg1, mcg2, and mcg3 having the highest number of isolates, respectively. mcg1 and mcg6 were found in all three studied regions and on both hosts, while mcg4 was detected in urmia and salmas on both hosts. other mcgs with multiple isolates were restricted to one or two regions and one host only. the total mcg richness among all 136 isolates was 12.5%, with cabbage isolates exhibiting a greater mcg richness of 18.6% than sunflower isolates, which had a smaller mcg richness of 12.9%. salmas had the highest level of diversity among the regional populations, with a mean mcg richness of 29.6%. a significant difference in lesion diameter on detached leaves of sunflower and cabbage was observed among the isolates. significant differences were observed in the lesion diameters of isolates from hosts, mat genotypes, and mcgs, all at a statistically significant level of 1%. the isolates from cabbage, and those with a heterokaryon genotype demonstrated higher aggressiveness compared to sunflower isolates, and other mat genotypes, respectively.